Dashboard settings not updating

I’ve updated from 2.6, to 2.7 about two weeks ago, and during this time I haven’t really tried to personalize the Dashboard. But now that I’ve tried, I see that it is not displaying all the widgets. I checked them all, but it’s just displaying: Right now, Quick Press, Recent Drafts, WordPress dev blog, and WordPress recent news. And that’s it, no matter what I choose in the settings. If I drag them around, the changes are not saved. As soon as I go somewhere else, it sets back to default.